U.S. patent application number 12/926431 was filed with the patent office on 2012-01-26 for pre-doping system of electrode and pre-doping method of electrode using the same.
This patent application is currently assigned to SAMSUNG ELECTRO-MECHANICS CO., LTD.. Invention is credited to Dong Hyeok Choi, Hyun Chul Jung, Bae Kyun Kim, Hak Kwan Kim, Hong Seok Min.
Application Number | 20120018309 12/926431 |
Document ID | / |
Family ID | 45492685 |
Filed Date | 2012-01-26 |
United States Patent
Application |
20120018309 |
Kind Code |
A1 |
Min; Hong Seok ; et
al. |
January 26, 2012 |
Pre-doping system of electrode and pre-doping method of electrode
using the same
Abstract
The present invention provides a pre-doping system of an
electrode and a system using the same. The pre-doping system
includes: a doping means for performing a doping process where
lithium ions are doped into an electrode; a measuring means for
performing a measuring process where an open-circuit potential of
the electrode is measured; a switch unit for selectively performing
any one of the doping process and the measuring process; a
controller for controlling the doping means, the measuring means,
and the switch unit and acquiring the open-circuit potential of the
electrode measured by the measuring means.
Inventors: |
Min; Hong Seok; (Yongin-si,
KR) ; Kim; Bae Kyun; (Seongnam-si, KR) ; Jung;
Hyun Chul; (Yongin-si, KR) ; Choi; Dong Hyeok;
(Suwon-si, KR) ; Kim; Hak Kwan; (Hanam-si,
KR) |
Assignee: |
SAMSUNG ELECTRO-MECHANICS CO.,
LTD.
Suwon
KR
|
Family ID: |
45492685 |
Appl. No.: |
12/926431 |
Filed: |
November 17, 2010 |
Current U.S.
Class: |
205/83 ;
204/229.8 |
Current CPC
Class: |
C25D 3/54 20130101; H01M
4/1393 20130101; H01M 4/139 20130101; Y02E 60/10 20130101; H01M
4/13 20130101; H01M 4/133 20130101; C25D 21/12 20130101; H01M
4/0459 20130101 |
Class at
Publication: |
205/83 ;
204/229.8 |
International
Class: |
C25D 21/12 20060101
C25D021/12; C25D 17/00 20060101 C25D017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 26, 2010 |
KR |
10-2010-0071934 |
Claims
1. A pre-doping system of an electrode comprising: a doping means
for performing a doping process where lithium ions are doped into
an electrode; a measuring means for performing a measuring process
where an open-circuit potential of the electrode is measured; a
switch unit for selectively performing any one of the doping
process and the measuring process; and a controller for controlling
the doping means, the measuring means, and the switch unit and
acquiring the open-circuit potential of the electrode measured by
the measuring means.
2. The pre-doping system of an electrode according to claim 1,
wherein the doping means comprises: a doping bath for receiving
electrolytic solution in which the electrode is immersed; and a
metal which supplies the lithium ions and is immersed together with
the electrode into the electrolytic solution.
3. The pre-doping system of an electrode according to claim 2,
further comprising a separator provided on one surface of the metal
facing the electrode.
4. The pre-doping system of an electrode according to claim 1,
wherein the switch unit comprises: one terminal connected to a
common contact electrically connected to a supply source of the
lithium ions; and the other terminal selectively connected to any
one of a first contact and a second contact, the first contact
being electrically connected to the electrode and the second
contact being electrically connected to the electrode through the
measuring means.
5. The pre-doping system of an electrode according to claim 1,
wherein the electrode includes a current collector and an active
material layer which is disposed at least one surface of the
current collector and reversibly dopes or un-dopes the lithium
ions.
6. The pre-doping system of an electrode according to claim 1,
further comprising a temperature controller for controlling a
temperature of the doping means.
7. The pre-doping system of an electrode according to claim 6,
further comprising a heating means for heating the doping means by
the temperature controller.
8. The pre-doping system of an electrode according to claim 1,
further comprising a moving means for inputting and outputting the
electrode and the supply source of the lithium ions into and out of
the doping means.
9. The pre-doping system of an electrode according to claim 8,
wherein the moving means comprises: a carrier for seating and
moving the electrode and the supply source of the lithium ions; a
sliding rail for guiding movement of the carrier; and a driving
unit for moving the carrier on the slide rail.
10. The pre-doping system of an electrode according to claim 1,
wherein the supply source of the lithium ions include a metal
containing the lithium ions, the metal being disposed to face the
electrode.
11. A pre-doping system of an electrode comprising: a doping bath
for receiving electrolytic solution; a carrier for inputting and
outputting an electrode and a metal into and from the electrolytic
solution received in the doping bath; a sliding rail for guiding
the movement of the carrier; a driving unit for moving the carrier
on the slide rail; a measuring means for measuring an open-circuit
potential of the electrode; and a switch unit for selectively
connecting the electrode, the metal, and the measuring means.
12. The pre-doping system of an electrode according to claim 11,
wherein the switch unit comprises: one terminal connected to a
common contact electrically connected to the metal; and the other
terminal selectively connected to any one of a first contact and a
second contact, the first contact being electrically connected to
the electrode and the second contact being electrically connected
to the electrode through the measuring means.
13. The pre-doping system of an electrode according to claim 11,
wherein the driving unit comprises: a driving motor for generating
a driving force; a timing belt rotated by the driving force; and a
lead screw for moving the carrier by the rotation of the timing
belt.
14. The pre-doping system of an electrode according to claim 11,
further comprising a heating means for adjusting a temperature of
the electrolytic solution, the heating means being disposed on a
lower portion of the doping bath.
15. The pre-doping system of an electrode according to claim 11,
further comprising a display device for outputting an open-circuit
potential of the electrode in real time.
16. The pre-doping system of an electrode according to claim 15,
wherein the display device further comprises an input device for
inputting operation signals used to operate the driving unit, the
measuring means, and the switch unit.
17. The pre-doping system of an electrode according to claim 16,
wherein the input device comprise a touch panel.
18. The pre-doping system of an electrode according to claim 11,
further comprising a separator formed on one surface of the metal
facing the electrode.
19. The pre-doping system of an electrode according to claim 11,
wherein the electrode includes terminals exposed from the
electrolytic solution.
20. The pre-doping system of an electrode according to claim 11,
wherein the electrode includes a current collector, and an active
material layer which is disposed at least one surface of the
current collector and reversibly dopes or un-dopes the lithium
ions.
21. A method for pre-doping an electrode comprising: immersing a
metal and an electrode into electrolytic solution; doping lithium
ions into the electrode from the metal; measuring an open-circuit
potential of the electrode; and repeatedly performing the doping
and measuring steps until the open-circuit potential of the
electrode reaches a preset value.
22. The method for pre-doping an electrode according to claim 21,
wherein the step of measuring the open-circuit potential is
performed after the doping process of the electrode is stopped.
23. The method for pre-doping an electrode according to claim 21,
further comprising a step of adjusting a temperature of the
electrolytic solution, before the doping process of the electrode.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. Section
[120, 119, 119(e)] of Korean Patent Application Serial No.
10-2010-0071934, entitled "Pre-Doping System Of Electrode And
Pre-Doping Method Of Electrode Using The Same", filed on Jul. 26,
2010, which is hereby incorporated by reference in its entirety
into this application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a pre-doping system of an
electrode; and, more particularly, to a pre-doping system of an
electrode and a pre-doping method for an electrode using the
same.
[0004] 2. Description of the Related Art
[0005] In general, an electrochemical energy storage apparatus
refers to a core component of finished products essentially used in
electronic appliances. Also, the electrochemical energy storage
apparatus is expected to be certainly used as a high-quality energy
source in renewable energy fields applicable to future electric
vehicles, portable electronic devices, and so on.
[0006] An electrochemical capacitor of electrochemical energy
storage apparatuses may be classified into an electrical double
layer capacitor using an electrical double layer principle and a
hybrid super-capacitor using electrochemical oxidation-reduction
reactions.
[0007] Herein, the electrical double layer capacitor is mainly used
in a field requiring high-output energy characteristics, but it has
a disadvantage such as low capacitance. On the contrary, the hybrid
super-capacitor has been actively researched as an alternative
solution for improving capacitance characteristics of the
electrical double layer capacitor. In particular, a Lithium Ion
Capacitor LIC of hybrid super-capacitors may have a storage
capacitance four times as large as that of the electrical double
layer capacitor.
[0008] The formation of an LIC may be made by a stacking process, a
welding process, a pre-processing doping process, and a sealing
process. In the stacking process, anodes, separators, and cathodes
in sheet shapes are stacked one on another to thereby form an
electrode stacked structure. In the welding process, terminals of
the anodes and the cathodes are respectively welded. In the
pre-processing process, lithium ions are pre-doped into the
cathodes. In the sealing process, the electrode stacked structure
is sealed with aluminum.
[0009] Herein, the pre-processing process for pre-doping the
lithium ions into the cathodes may be made by forming lithium
metallic films on each of the uppermost layer and lowermost layer
of the electrode stacked structure, and then immersing it into
electrolytic solution. This pre-doping process involves
charging/discharging processes several-times, the charging process
being made by applying voltages to anodes and cathodes in
electrolytic solution and the discharging process being made
between the anodes and lithium metal. Therefore, in case of the
pre-doping process, an additional device for applying external
currents/voltages should be installed. In addition, it takes 20
days to uniformly dope lithium ions into the cathodes provided
within the electrode stacked structure, which results in a
difficulty for mass-production.
[0010] At this time, by performing the pre-doping process for
pre-doping the cathodes before the stacking process, and then the
stacking process for stacking the cathodes and the separators and
the anodes, it is possible to shorten a time taken for the
pre-doping process.
[0011] However, the number of electrodes stacked in a
high-capacitance LIC becomes increased, and thus the process time
lengthens in manufacturing the LIC with a limited high-capacitance.
This is because each of the cathodes should be subjected to the
doping process.
[0012] Also, the cathodes doped with the lithium ions are
significantly sensitive to moisture and thus it is not easy to
treat. Therefore, it is difficult to verify the doping level of the
cathodes during the doping process and in an assembling process
followed by the process, which results in limitation to reliability
and mass-production of the LIC.
[0013] Thus, there was a trial to perform the pre-doping process
for the cathodes before the stacking process to improve the
mass-production of the LIC. However, it was impossible to actually
control the pre-doping process for the cathodes.
SUMMARY OF THE INVENTION
[0014] The present invention has been proposed in order to overcome
the above-described problems and it is, therefore, an object of the
present invention to provide a pre-doping system of an electrode
which is provided with a measuring means for measuring an
open-circuit potential of an electrode to thereby control a
pre-doping process of the electrode, and a pre-doping method of the
electrode using the same.
[0015] In accordance with one aspect of the present invention to
achieve the object, there is provided an electrode pre-doping
system including: a doping means for performing a doping process
where lithium ions are doped into an electrode; a measuring means
for performing a measuring process where an open-circuit potential
of the electrode is measured; a switch unit for selectively
performing any one of the doping process and the measuring process;
a controller for controlling the doping means, the measuring means,
and the switch unit and acquiring the open-circuit potential of the
electrode measured by the measuring means.
[0016] Also, the doping means includes: a doping bath for receiving
electrolytic solution in which the electrode is immersed; and a
metal which supplies the lithium ions and is immersed together with
the electrode into the electrolytic solution.
[0017] Also, the system further includes a separator provided on
one surface of the metal facing the electrode.
[0018] Also, the switch unit includes: one terminal connected to a
common contact electrically connected to a supply source of the
lithium ions; and the other terminal selectively connected to any
one of a first contact and a second contact, the first contact
being electrically connected to the electrode and the second
contact being electrically connected to the electrode through the
measuring means.
[0019] Also, the electrode includes a current collector, and an
active material layer which is disposed at least one surface of the
current collector and reversibly dopes or un-dopes the lithium
ions.
[0020] Also, the system further includes a temperature controller
for controlling a temperature of the doping means.
[0021] Also, the system further includes a heating means for
heating the doping means by the temperature controller.
[0022] Also, the system further includes a moving means for
inputting and outputting the electrode and the supply source of the
lithium ions into and out of the doping means.
[0023] Also, the moving means includes: a carrier for seating and
moving the electrode and the supply source of the lithium ions; a
sliding rail for guiding movement of the carrier; and a driving
unit for moving the carrier on the slide rail.
[0024] Also, the supply source of the lithium ions includes a metal
containing the lithium ions, the metal being disposed to face the
electrode.
[0025] In accordance with another aspect of the present invention
to achieve the object, there is provided a pre-doping system of an
electrode including: a doping bath for receiving electrolytic
solution; a carrier for inputting and outputting an electrode and a
metal into and from the electrolytic solution received in the
doping bath; a sliding rail for guiding the movement of the
carrier; a driving unit for moving the carrier on the slide rail; a
measuring means for measuring an open-circuit potential of the
electrode; and a switch unit for selectively connecting the
electrode, the metal, and the measuring means.
[0026] Also, the switch unit includes: one terminal connected to a
common contact electrically connected to the metal; and the other
terminal selectively connected to any one of a first contact and a
second contact, the first contact being electrically connected to
the electrode and the second contact being electrically connected
to the electrode through the measuring means.
[0027] Also, the driving unit includes: a driving motor for
generating a driving force; a timing belt rotated by the driving
force; and a lead screw for moving the carrier by the rotation of
the timing belt.
[0028] Also, the system further includes a heating means for
adjusting a temperature of the electrolytic solution, the heating
means being disposed on a lower portion of the doping bath.
[0029] Also, the system further includes a display device for
outputting an open-circuit potential of the electrode in real
time.
[0030] Also, the display device further comprises an input device
for inputting operation signals used to operate the driving unit,
the measuring means, and the switch unit.
[0031] Also, the input device includes a touch panel.
[0032] Also, the system further includes a separator formed on one
surface of the metal facing the electrode.
[0033] Also, the electrode includes terminals exposed from the
electrolytic solution.
[0034] Also, the electrode includes a current collector, and an
active material layer which is disposed at least one surface of the
current collector and reversibly dopes or un-dopes the lithium
ions.
[0035] In accordance with still another aspect of the present
invention to achieve the object, there is provided a method for
pre-doping an electrode including the steps of: immersing a metal
and an electrode into electrolytic solution; doping lithium ions
into the electrode from the metal; measuring an open-circuit
potential of the electrode; and repeatedly performing the doping
and measuring steps until the open-circuit potential of the
electrode reaches a preset value.
[0036] Also, the step of measuring the open-circuit potential is
performed after the doping process of the electrode is stopped.
[0037] Also, the system further includes a step of adjusting a
temperature of the electrolytic solution, before the doping process
of the electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] These and/or other aspects and advantages of the present
general inventive concept will become apparent and more readily
appreciated from the following description of the embodiments,
taken in conjunction with the accompanying drawings of which:
[0039] FIG. 1 is a schematic-view showing a system for pre-doping
an electrode in accordance with a first embodiment of the present
invention;
[0040] FIG. 2 is a cross-sectional view showing a detailed shape of
the system for pre-doping the electrode in accordance with a first
embodiment of the present invention;
[0041] FIG. 3 is a top view showing the system for pre-doping the
electrode shown in FIG. 2; and
[0042] FIG. 4 is a flowchart showing a process of pre-doping the
electrode in accordance with a second embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERABLE EMBODIMENTS
[0043] Embodiments of a system for pre-doping an electrode in
accordance with the present invention will be described in detail
with reference to the accompanying drawings. When describing them
with reference to the drawings, the same or corresponding component
is represented by the same reference numeral and repeated
description thereof will be omitted.
[0044] FIG. 1 is a schematic view showing a system of pre-doping an
electrode in accordance with a first embodiment of the present
invention.
[0045] Referring to FIG. 1, a system of pre-doping an electrode 100
(hereinafter, referred to as "electrode pre-doping system 100") in
accordance with the first embodiment of the present invention may
include a doping means 110, a switch unit 130, a measuring means
140, and a controller 150.
[0046] The electrode pre-doping system 100 may be used to dope
lithium ions into cathodes before anodes, separators, and cathodes
are stacked to manufacture an LIC.
[0047] The doping means 110 may play a role of performing a doping
process for the electrode 120. The doping means 110 may include a
doping bath 111 and metal 113.
[0048] Herein, the doping bath 111 may be provided with opened
upper surfaces as a bath for receiving electrolytic solution 112.
Thus, it is possible to input and output the electrode 120 and the
metal 113 into and out of the doping bath 111 with ease. The
electrolytic solution 112 plays a role of a medium for transferring
lithium ions, and it may be formed of a material which makes
lithium ions stable owing to non-occurrence of electrolysis at a
high voltage. For example, the electrolytic solution 112 may
include a solvent with dissolved lithium salt therein. As for the
lithium salt, LiPF6, LiBF4, LiClO4, and so on may be exemplified.
Also, as for the solvent, an organic solvent with non-proton
property may be exemplified. However, the material of the
electrolytic solution 112 is not limited by the embodiment of the
present invention.
[0049] Also, the metal 113 may serve as a supply source of lithium
ions doped into the electrode 120. That is, the metal 113 may be
materials containing lithium ions, such as lithium and lithium
alloy. At this time, in case where the metal 113 and the electrode
120 are short-circuited, due to a potential difference between the
metal 113 and the electrode 120, the lithium ions may be doped into
the electrode 120.
[0050] Herein, a separator 114 may further be disposed on one
surface of the metal 113 opposed to the electrode 120. The
separator 114 may play a role of preventing the metal 113 from
directly contacting the electrode 120. This is because a doping
process is controlled with no ease and a uniform doping process for
the electrode 120 is not guaranteed as there is a possibility of
performing a doping process due to direct contact between the metal
113 and the electrode 120. That is, the separator 114 may play a
role of stabilizing the doping process of the electrode 120.
[0051] The switch unit 130 may play a role of selecting any one of
the doping process of the electrode 120 and a measuring process of
an open-circuit potential in the electrode 120. Herein, the switch
unit 130 may include a relay switch. For example, the switch unit
130 may include one terminal connected to a common contact 131, and
the other terminal connected selectively to any one of first and
second contacts 132 and 133. At this time, the common contact 131
may be electrically connected to the metal 113. Also, the first
contact 132 may be electrically connected to the electrode 120.
Also, the second contact 133 may be electrically connected to the
electrode 120 through the measuring means 140.
[0052] Thus, by the switching operation of the switch unit 130, the
doping process by the doping means 110 or the measuring process by
the measuring means 140 may be selectively performed.
[0053] The measuring means 140 measures the open-circuit potential
of the electrode 120. Herein, when the electrode 120 and the metal
113 are open-circuited within the electrolytic solution 112, the
open-circuit potential of the electrode 120 may be a potential
value of a reference electrode (i.e. the electrode 120 measured by
connecting the metal 113 to the measuring means 140) immersed
within the electrolytic solution 112. Herein, the open-circuit
potential of the electrode 120 may be varied according to doping
amount of lithium ions doped into the electrode 120. For example,
the more the lithium ions doped into the electrode 120, the lower
the open-circuit potential of the electrode 120. Thus, a doping
level may be verified by the open-circuit potential of the
electrode 120 measured by the measuring means 140.
[0054] The controller 150 controls the doping and measuring
processes and acquires information about the open-circuit potential
of the electrode 120 measured by the measuring means 140. Herein,
under the control of the controller 150, the switch unit 130
connected to the controller 150 may selectively perform any one of
the doping process and the measuring process according to control
commands.
[0055] Also, the controller 150 is connected to the measuring means
140 to thereby apply measuring signals for measuring the
open-circuit potential of the electrode 120 to the measuring means
140. Also, the controller 150 may acquire data measured from the
measuring means 140 according to measuring signals, that is,
information on the open-circuit potential of the electrode 120.
[0056] In addition, the electrode pre-doping system 100 may further
include a temperature controller 160 for controlling the
temperature of the doping means 110, that is, the temperature of
the electrolytic solution 112 received in the doping bath 111, so
as to control the speed of the doping process. This means that
since the doping speed is influenced by the temperature of the
electrolytic solution 112, the doping speed can be controlled
according to the temperature of the electrolytic solution 112.
[0057] The temperature controller 160 may be connected to the
controller 150. At this time, the temperature controller 160 may
control the temperature of the doping means 110 according to
temperature control commands provided from the controller 150.
Also, the temperature controller 160 may provide the temperature
information of the doping means 110 to the controller 150. Upon
receiving the temperature information, the controller 150 may
generate temperature control commands for the temperature
controller 160 on the basis of the received temperature information
of the doping means 110.
[0058] Also, the electrode pre-doping system 100 may further
include a moving means for inputting and outputting the electrode
120 into and from the doping means 110. Herein, the moving means
may input the metal 113, together with the electrode 120, within
the doping means 110. The moving means may include a carrier, a
sliding rail, and a driving unit. The carrier moves the electrode
120 seated thereon, and the sliding rail guides the carrier to be
moved. The driving unit moves the carrier on the sliding.
[0059] Also, the electrode pre-doping system 100 may further
include a display device for real-time outputting the open-circuit
potential of the electrode 120 after receiving the open-circuit
potential from the controller 150.
[0060] Also, the electrode pre-doping system 100 may further
include an input device for receiving operation signals inputted
for operation of the electrode pre-doping system 100. Therefore, it
is possible for a worker to operate the electrode pre-doping system
through the input device. Herein, the input device may be in a
shape of a touch panel installed in the display device.
[0061] Meanwhile, the electrode 120 may have a cathode of the
lithium ion capacitor.
[0062] The electrode 120 may include a current collector 121 and an
active material layer 122 which is disposed on at least one surface
of the current collector 121 and is capable of reversibly doping or
un-doping the lithium ions. Herein, the current collector 121 may
be formed in a metal mesh or a metal foil. At this time, the metal
may include any one of Cu and Ni, but the present invention is not
limited thereto. Also, the active material layer 122 may include a
carbon material capable of reversibly doping and un-doping lithium
ions, e.g., graphite.
[0063] In addition, the electrode 120 may further include a
terminal 123 which extends from one end of the current collector
121 to be electrically connected to an external circuit unit. At
this time, the terminal 123 may be protruded from the current
collector 121. That is, the terminal 123 may be integrated with the
current collector 121.
[0064] Herein, in case where the electrode 120 is immersed into the
electrolytic solution 112 for its doping process, the terminal 123
of the electrode 120 may be exposed. This is because when the
terminal 123 is contaminated by the electrolytic solution 112,
fusion failure may occur during a fusion process of the terminal
123 performed to form the lithium ion capacitor.
[0065] Although it has been shown and illustrated in the embodiment
of the present invention that the pre-doping process of the
electrode 120 is performed for one electrode 120, the present
invention is not limited thereto. Also, a plurality of electrodes
may be individually subjected to the pre-doping process.
[0066] As in the embodiment of the present invention, in case where
lithium ions are doped into the electrode 120 by using the
electrode pre-doping system 100, it is possible to monitor a doping
level of the electrode 120 in real time. Therefore, it is possible
to prevent the actual doping amount from being less than or greater
than a preset doping amount. Thus, in case where a pre-doped
cathode by the electrode pre-doping system 100 is used to
manufacture a lithium ion capacitor, it is possible to improve
reliability and cycle characteristics of the lithium ion
capacitor.
[0067] Also, by the electrode pre-doping system 100 of the present
invention, it is possible to verify the doping level of the
electrode 120 in real time, thereby controlling the pre-doping
process of the electrode 120. Thus, the electrode pre-doping system
100 may be easily applied for mass-production through a process
design. Also, the electrode pre-doping system 100 may control the
speed of the doping process by be additionally provided with the
temperature controller 160.
[0068] FIG. 2 is a cross-sectional view showing a detailed shape of
the electrode pre-doping system in accordance with the first
embodiment of the present invention.
[0069] FIG. 3 is a top view showing the electrode pre-doping system
shown in FIG. 2.
[0070] Referring to FIGS. 2 and 3, the electrode pre-doping system
100 in accordance with the first embodiment of the present
invention may include the doping bath 111, a carrier 210, a sliding
rail 220, a driving unit 230, the measuring means 140, and the
switch unit 130.
[0071] The doping bath 111 may receive the electrolytic solution
112 for transferring the lithium ions. The doping bath 111 may be
provided with opened upper surfaces. At this time, the electrode
120 and the metal 113 inputted into the doping bath 111 through the
opened upper surfaces may be immersed into the active material
layer 122 received in the doping bath 111.
[0072] The doping bath 111 may be fixed by a frame 300 disposed at
an external side.
[0073] The carrier 210 may play a role of moving the electrode 120
seated thereon. Herein, the electrode 120 may include a current
collector 121 and an active material layer 122 which is disposed on
at least one surface of the current collector 121 and is capable of
reversibly doping and un-doping lithium ions. In addition, the
electrode 120 may further include the terminal 123 which extends
from one end of the current collector 121 to be electrically
connected to an external circuit unit.
[0074] The carrier 210 may move the electrode 120 together with the
metal seated thereon. Herein, the metal 113 may serve as a supply
source of lithium ions and may be formed of a material, such as
lithium and lithium alloy. In addition to this, a separator is
further provided on one surface of the metal 113 opposed to the
electrode 120, thereby stabilizing the doping process.
[0075] The carrier 210 may seat the metal 113 and the active
material layer 122 of the electrode 120 to face each other. For
example, in case where the electrode 120 includes the current
collector 121 whose both sides are provided with the active
material layer 122, the metal 113 may be disposed to face each of
the sides of the electrode 120.
[0076] In order to perform the doping process of the electrode 120,
the carrier 210 may make the electrode 120 and the metal 113
immersed into the electrolytic solution 112 received in the doping
bath 111 by being lowered from the upper portion to the lower
portion of the doping bath 111. At this time, the terminal 123 of
the electrode 120 is allowed to be exposed from the electrolytic
solution 112, so as to prevent the terminal 123 of the electrode
120 from being contaminated by the electrolytic solution 112. Also,
in case where the doping process of the electrode 120 is completely
performed, the carrier 210 is raised from the downside to the
upside of the doping bath 111, so that it is possible to output the
electrode 120 and the metal 113 from the electrolytic solution
112.
[0077] The sliding rail 220 may be connected to the carrier 210 and
may be disposed on an external side of the doping bath 111. At this
time, the sliding rail 220 may be fixed by the frame 300. Herein,
the sliding rail 220 may play a role of guiding movement of the
carrier 210.
[0078] The driving unit 230 may be fixed by the frame 300 disposed
on an external side of the doping bath 111. Herein, the driving
unit 230 may include a driving motor 231, a timing belt 232, and a
lead screw 233. The driving motor 231 forms a driving force, and
the timing belt 232 is rotated by the driving force provided from
the driving motor 231. The lead screw 233 lifts and lowers the
carrier 210 by rotation of the timing belt 232 connected to the
timing belt 232. At this time, the lead screw 233 and the sliding
rail 220 may be fixed by the frame 300 disposed at an external side
of the doping bath 111 with a parallel relation to each other.
[0079] The measuring means 140 may be disposed on an external side
of the doping bath 111. Herein, the measuring means 140 is disposed
on the external side of the frame 300. However, preferably, the
measuring means 140 may be laid inside the frame 300.
[0080] The measuring means 140 may play a role of measuring the
open-circuit potential of the electrode 120 in order to verify the
doping level of the electrode 120 while the electrode 120 is being
subjected to the doping process. Herein, the measuring means 140
may perform the measuring process after stopping the doping process
of the electrode 120. The measuring means 140 may use the metal 113
as a reference electrode. At this time, the measuring means 140 is
electrically connected to the metal 113 to thereby measure the
potential of the electrode 120 immersed into the electrolytic
solution 112.
[0081] Thereafter, after the measuring process is completely
performed by the measuring means 140, the electrode 120 and the
metal 113 are made short-circuited to re-perform a doping process
of the electrode 120. Thus, the open-circuit potential of the
electrode 120 is measured during the doping process of the
electrode 120, so that it is possible to verify the doping level in
real time.
[0082] It has been shown that the switch unit 130 is disposed at an
external side of the frame 300. However, preferably, the switch
unit 130 may be laid inside the frame 300, together with the
measuring means 140.
[0083] The switch unit 130 may selectively connect the electrode
120, the metal 113, and the measuring means 140. That is, the
switch unit 130 may allow the electrode pre-doping system 100 to
selectively perform the doping process or the measuring process.
Herein, the switch unit 130 may be a relay switch. For example, the
switch unit 130 may include one terminal connected to the common
contact 131, and the other terminal connected selectively to any
one of the first and second contacts 132 and 133. At this time, the
common contact 131 may be electrically connected to the metal 113.
Also, the first contact 132 may be electrically connected to the
electrode 120, and the second contact 133 may be electrically
connected to the electrode 120 through the measuring means 140.
Thus, the switching operation of the switch unit 130 may allow the
doping process or the measuring process to be selectively
performed.
[0084] In addition to this, the electrode pre-doping system 100 may
further include a display device 400 for real-time outputting the
open-circuit potential of the electrode 120 measured by the
measuring means 140. It is possible for a worker to control the
pre-doping process of the electrode 120 by monitoring the
open-circuit potential of the electrode 120 provided from the
display device 400.
[0085] Also, the electrode pre-doping system 100 may further
include an input divide for inputting operation signals used to
operate the driving unit 230, the measuring means 140, and the
switch unit 130. Herein, the input device may be implemented in a
touch panel provided in the display device 400.
[0086] Also, the display device 400 may output control signals for
controlling the driving unit 230, the measuring means 140, and the
switch unit 130 according to the operation signals by being
provided with the controller, that is, a Micro Control Unit
(MCU).
[0087] Also, a heating means 170 may further be disposed on a lower
portion of the doping bath 111. The heating means 170 may maximize
the doping process of the electrode 120 by increasing the
temperature of the electrolytic solution 112 received in the doping
bath 111 up to a predetermined temperature. Herein, the
predetermined temperature may be a temperature of 60.degree. C.,
but the present invention is not limited thereto.
[0088] Also, the electrode pre-doping system 100 may further
include the temperature controller 160 which is connected to the
heating means 170 to control the heating means 170. Herein, the
temperature controller 160 controls the heating means 170 according
to the temperature control commands provided from the MCU, thereby
adjusting the temperature of the electrolytic solution 112. Also,
the temperature controller 160 may provide the temperature of the
electrolytic solution 112 to the MCU. At this time, based on the
information about the temperature conditions of the electrolytic
solution, the MCU can provide the temperature control commands to
the temperature controller 160. Thus, it is possible to adjust the
doping process speed of the electrode 120 according to the doping
level of the electrode 120, which results in an increase of
production's efficiency for the electrode 120.
[0089] Hereinafter, with reference to FIG. 4, an electrode
pre-doping process in accordance with a second embodiment of the
present invention will be described in more detail.
[0090] FIG. 4 is a flowchart showing a process of pre-doping the
electrode in accordance with a second embodiment of the present
invention.
[0091] Referring to FIG. 4, in order to perform the electrode
pre-doping process in accordance with a second embodiment of the
present invention, first, it is judged whether the temperature of
the electrolytic solution corresponds to a temperature set to
efficiently perform the electrode pre-doping process. Although it
is assumed that the preset temperature of the electrolytic solution
is a temperature of 60.degree. C., the present invention is not
limited thereto. The preset temperature of the electrolytic
solution may be changed depending on process factors of the
electrode pre-doping process, for example, electrode's shape,
electrode's doping level, the kind of electrolytic solution, and so
on. (step S10).
[0092] Herein, when it is judged that the temperature of the
electrolytic solution fails to reach the preset temperature, the
temperature of the electrolytic solution is controlled. At this
time, the temperature of the electrolytic solution may be
controlled through the heating means disposed on the lower portion
of the doping bath receiving the electrolytic solution (step S11).
Thereafter, when the temperature of the electrolytic solution is
controlled by the heating means, the step S10 is again
performed.
[0093] In step S10, it is judged whether the temperature of the
electrolytic solution reaches the preset temperature. When it is
judged that the temperature of the electrolytic solution reaches
the preset temperature, the metal and the electrode are immersed
into the electrolytic solution. Herein, the metal may play a role
of a supply source of lithium ions, as a metal containing the
lithium ions. At this time, the metal and the active material layer
of the electrode may be disposed to face each other (step S20).
[0094] The metal and the electrode immersed into the electrolytic
solution are made short-circuited. Due to the potential difference
between the metal and the electrode, the lithium ions of the metal
may be doped into the electrode. A process for doping the lithium
ions into the electrode is performed (step S30).
[0095] The doping process, that is, short-circuit of the metal and
the electrode, are maintained until a set time (step S40), and then
the metal and the electrode are made open-circuited. The
open-circuit between the metal and the electrode may allow the
doping process of the electrode to be stopped (step S50).
[0096] After the metal and the electrode are made open-circuited,
the open-circuit potential of the electrode is measured. Herein,
the open-circuit potential of the electrode may be measured by
using the metal as the reference electrode. At this time, the
open-circuit potential of the electrode may be reduced depending on
the doping amount of the electrode. That is, by measuring the
open-circuit potential of the electrode, it is possible to verify
the doping level of the electrode (step S60).
[0097] It is judged whether the open-circuit potential of the
electrode coincides with a preset open-circuit potential, after the
open-circuit potential of the electrode is measured (step S70).
[0098] Herein, when it is judged that the open-circuit potential of
the electrode fails to reach the preset open-circuit potential of
the electrode, the following steps are repeatedly performed. The
steps includes the steps of making the electrode and the metal
short-circuited (step S30), keeping the electrode and the metal
short-circuited for a predetermined time (step S40), making the
electrode and the metal open-circuited (step S50), and measuring
the open-circuit potential of the electrode (step S60).
[0099] When it is judged that the open-circuit potential of the
electrode reaches the preset open-circuit potential of the
electrode, the electrode is outputted from the electrolytic
solution (step S80), thereby terminating the electrode pre-doping
process. At this time, the metal may be outputted together with the
electrode from the electrolytic solution.
[0100] Therefore, as in the embodiment of the present invention, in
the electrode pre-doping process, the open-circuit potential of the
electrode is measured, so that it is possible to verify the doping
level of the electrode on real time during the doping process.
[0101] The electrode pre-doping system according to the present
invention is provided with the measuring means for measuring the
open-circuit potential of the electrode, so that it is possible to
verify the doping level of the electrode. Therefore, it is possible
to improve reliability and cycle characteristics of the LIC.
[0102] Also, the electrode pre-doping system according to the
present invention is provided with the measuring means to thereby
control the pre-doping process of the electrode, so that it is
possible to be applicable to mass-production through a
process-design.
[0103] Also, the electrode pre-doping system according to the
present invention is further provided with the temperature
controller, so that it is possible to control the speed of the
doping process.
[0104] As described above, although the preferable embodiments of
the present invention have been shown and described, it will be
appreciated by those skilled in the art that substitutions,
modifications and variations may be made in these embodiments
without departing from the principles and spirit of the general
inventive concept, the scope of which is defined in the appended
claims and their equivalents.
* * * * *